Lethal Effects of Pyriproxyfen on Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae)

Abstract

Lethal effect of pyriproxyfen, a pyridine based juvenile hormone analogue with mode of action different from the conventional insecticides are reported against the different stages of whitefly, Bemisia tabaci (Gennadius). Various toxicity values during the two year evaluation i.e. LC30 (0.020, 0.021%) and LC50 (0.043, 0.048%) against the first instar nymphs; LC30 (0.026, 0.029%) and LC50 (0.055, 0.060%) against the fourth instar nymphs; LC30 (0.031, 0.034%) and LC50 (0.061, 0.069%) against the adults were worked out by employing standard methods of bioassay. Strong ovicidal activity, with 94.24 and 91.42 per cent annihilation of egg hatch of B. tabaci was observed when the eggs were dipped in the highest concentration (0.16 per cent) of pyriproxyfen during 2016 and 2017, respectively. Mortality of the first instar nymphs (47.72 and 45.85%) on lower surface of cotton leaves indicated pronounced translaminar effect during both the years. In the light of its non-toxic effect against the bio-control agents, pollinators and mammals and lethal effect against various stages of B. tabaci, and its translaminar effect, pyriproxyfen can be used as an effective tool for management of the pest.